Centre National De La Recherche Scientifique

Thomson-csf

Denis Jerome

Klaus Bechgaard

Louis Giral

Alexandre Moradpour

Philippe Michel

Claude More

Paul Penven

Patrick Batail

Serge J Bouffard

Jean M Fabre

Jean-Pierre Sorbier

Guy-Roland Roger

Michel Ribault

Libero Zuppiroli

Marc Fourmigue

Andre Fournel

Georges Tevanian

Jean-Marc Delrieu

The invention relates to a method of authenticating an object by electron paramagnetic resonance spectroscopy, the method being characterized in that at least one authenticating substance is added to the object, said substance having an EPR peak whose width is not greater than about 1.5 gauss, with the spectroscopy being performed in a static field of an amplitude such that the substance has a resonance frequency in the radio-frequency domain, and with the width of the EPR peak of the substance being used as a criterion for discrimination. The static field preferably has a low frequency colinear modulation field superposed thereon having an amplitude which is substantially greater than the EPR width of the substance, and under a radiofrequency electromagnetic field extending perpendicularly to the static field and to the modulation field and having an amplitude which is not less than the peak width, whereby paramagnetic materials having a peak width which is greater than that of the authenticating substance are not detected. The invention also provides apparatus for implementing the method, and security paper useable with the method.

Method of authenticating an object by electron paramagnetic resonance,

Disclosed is an organic material with a very narrow electronic spin resonance (ESR) line. This material is formed by a 1, 2, 7, 8-tetrahydrocyclopentataperylene salt which may have, advantageously, undergone a heat treatment. The material can be applied to the fabrication of probes for gaussmeters and magnetometers.

Organic material with extremely narrow electron spin resonance line and

Microcircuits composed of a plurality of alternating conducting and insulating regions are formed in a substrate of an organic quasi-unidimensional conductor such as .DELTA..sup.2,2 bi-4,5-dimethyl-1,3-diselenolylidene upon irradiation of the substrate with a precise beam of electrons having an energy of at least 1 keV, preferably at least 8 keV, which forms the insulating regions. When exposed to cryogenic temperatures the non-irradated conducting regions become super conducting. Using electron beam irradiations, sub-micronic resolution as low as 100 .ANG. can be achieved. Microcircuits having Josephson junctions and superconducting quantum interference devices are described.

Microcircuits formed from substrates of organic quasiunidimensional

Method of increasing the supraconductive critical temperature in quasi

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Jouy en Josas, France

Denis Jerome